Water Purification

In this section, we will cover water purification; it's purpose and the equipment required to achieve clean, healthy water.  The primary methods for purification include boiling, chemical treatment, and water filters.  They will be discussed in more detail later.

Unfortunately, the days of simply cupping your hands into a creek for a safe drink of water are over. Water purification is no longer just for water sources that look questionable; you should use some type of purification before drinking from any water source in the wilds.  In this section I will discuss the different methods for purifying your water, and the various diseases you can prevent by doing so.  

First, let’s discuss what evils can be lurking in that crystal-clear looking water! Giardiasis is the most common and widespread disease and is caused by microscopic parasitic cysts called giardia.  No surface water source is guaranteed to be unaffected by these cysts, including clear-looking mountain headwaters.   This intestinal disease is spread through oral-fecal transmission and is carried by humans and animals.  If you’ve seen the water filter ads in some of the outdoor magazines, you will see that animals are not often concerned with where they urinate or defecate.  Unfortunately, some humans are just as careless.  Without the precaution of staying at least 200 feet away from any water source and properly disposing of human waste, fecal matter can contaminate a widespread area.  

Giardiasis has an incubation period of seven to twenty-one days and must be diagnosed by a physician analyzing the victim’s stool for giardia’s microscopic cysts.  Some of the symptoms for giardiasis include bloating, diarrhea, headache, vomiting, flatulence, cramping, low-grade fever, and loss of appetite . . . need I go on?  It is not pleasant, by any means.  I know; I got giardia.  Beavers (along with humans and other animals—domestic and wild) are known carriers of the disease.  My filter clogged up and I needed water, so not having a way to purify water, I drank right out of the stream.  One thing to remember if you are in the same situation; always drink the water.  You can be treated for giardia later; death from dehydration is harder to treat!  Because of this situation, I now carry purification tablets as well as a filter.  The additional ounce in weight is well worth the safety net it provides.

Cryptosporidium is the next villain to be on the watch for, and it’s quickly becoming a serious problem in many areas, not just in the woods.  Like giardia, it is another microscopic cyst with the same transmission methods and many of the same symptoms.  This particular parasite is even becoming a threat in our municipal water supplies because of its high resistance to chlorine.  In 1993, Milwaukee had an outbreak of the waterborne cryptosporidium in its municipal water supply, which ended up affecting around 40,000 people!  As a desert dweller, I can’t stress enough how important water is and to respect it, take care of it, and never waste it. Kansas State University has a wonderful site on this particular villain. although it is rather technical. Los Angeles Water and Power also has a page describing crypto; just goes to show you that you aren't necessarily safe at home drinking your tap water!

Now on to water purification.  There are primarily three effective methods for purifying your water.  There is always the good old standby of boiling your water.  Contrary to earlier beliefs that had us boiling our water for five to ten minutes, just bringing your water to a boil is sufficient for killing anything harmful in the water.  This includes boiling at high elevations, even though the boiling point is much lower than at sea level.  The main disadvantage of boiling your water is carrying enough fuel to provide ample water for your trip.

The second method is by using chemical disinfectants, such as iodine or chlorine, to purify your water.  As I mentioned above, cryptosporidium is very resistant to this type of purification, so it is questionable how much longer this will be effective as our water sources become more contaminated.  One of the main problems with using iodine or chlorine is the taste they give the water.  A relatively recent improvement to this treatment is the addition of neutralizer tablets. The Potable Aguaä system uses chlorine tablets followed by a neutralizer (after the allotted time for treatment) to restore a decent flavor to the water.  The neutralizer is simple citric acid, or vitamin C, and it makes a tremendous difference in the flavor.  Having always been a staunch fan of water filters, even I can recommend this to those of you with discriminating taste buds but skinny wallets; your classic champagne taste on a beer budget!  It may not be perfect, but it certainly is a palatable way to disinfect your water in a lightweight and inexpensive manner.  There is some uncertainty of its shelf life, so, to be on the safe side, buy a new bottle before each trip.  Also remember you can add powdered drink mix to your water to improve its flavor.

And last, but certainly not least, let’s talk about water filters!  This is the method I prefer for treating my water.  The flavor is maintained, or even improved, by the use of water filters.    Unfortunately, there is no such thing as the perfect water filter.  They can not filter out viruses, and not all of them treat bacteria.  Filters usually provide plenty of protection; however, if you plan on traveling a lot, think seriously about the capability of treating water for viruses as well.   Hepatitis, among many other diseases, is a very real threat when traveling to certain countries.

Because there is no perfect water filter for every situation, be sure to compare and buy one suited to your needs.  Where will you be using it most?  How often will you use it?  How easy is it to use by yourself?  How comfortable is it to use?  These are all very important considerations; pumping can be extremely tiring, but your health and welfare rely on it.  Another thing to think about is the ability to clean the filter in the field. The reason I mention this is because of my giardia experience. The filter I had clogged up and nothing I did could clear it enough to even get a trickle to come out. Learn from my mistake and make sure you get something that doesn’t leave you stranded. Another thing to consider is the availability of replacement filter cartridges. What good is it to get a great filter that you will never be able to find the parts for?  My personal favorites  are designed so they are quite comfortable to pump, they pump at decent flow rates, and most importantly they are field-cleanable!   some water filters also have a model which kills all parasites, bacteria and viruses.  There are many other great filters out there.

Here are several more tips for water usage in the backcountry:

Updated:  07/28/00